Meg F/X can beep and click using a hardware timer so let us try it out. To match things up better, fix PCM beeping to give correct frequency (and get a pointer wrap bug too). Do some minor adjustments to compensate for corrections.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19355 a1c6a512-1295-4272-9138-f99709370657

3 files changed, 110 insertions, 6 deletions

diff --git a/firmware/target/arm/s3c2440/gigabeat-fx/kernel-meg-fx.c b/firmware/target/arm/s3c2440/gigabeat-fx/kernel-meg-fx.c
index 76917c8c82..5ef8c8023a 100644
--- a/firmware/target/arm/s3c2440/gigabeat-fx/kernel-meg-fx.c
+++ b/firmware/target/arm/s3c2440/gigabeat-fx/kernel-meg-fx.c
@@ -32,18 +32,18 @@ void tick_start(unsigned int interval_in_ms)
      * Timer input clock frequency =
      *      fPCLK / {prescaler value+1} / {divider value}
      * TIMER_FREQ = 49156800 / 2
-     * 13300 = TIMER_FREQ / 231 / 8
-     * 49156800 = 19*(11)*(7)*7*5*5*(3)*2*2*2*2*2*2
-     * 231 = 11*7*3
+     * 146300 = TIMER_FREQ / 21 / 8
+     * 49156800 = 19*11*(7)*7*5*5*(3)*2*2*2*2*2*2
+     * 21 = 7*3
      */
 
     /* stop timer 4 */
     TCON &= ~(1 << 20);
     /* Set the count for timer 4 */
-    TCNTB4 = (TIMER_FREQ / 231 / 8) * interval_in_ms / 1000;
+    TCNTB4 = (TIMER_FREQ / TIMER234_PRESCALE / 8) * interval_in_ms / 1000;
     /* Set the the prescaler value for timers 2,3, and 4 */
-    TCFG0 = (TCFG0 & ~0xff00) | ((231-1) << 8);
-    /* MUX4 = 1/16 */
+    TCFG0 = (TCFG0 & ~0xff00) | ((TIMER234_PRESCALE-1) << 8);
+    /* DMA mode off, MUX4 = 1/16 */
     TCFG1 = (TCFG1 & ~0xff0000) | 0x030000;
     /* set manual bit */
     TCON |= 1 << 21;
diff --git a/firmware/target/arm/s3c2440/gigabeat-fx/timer-target.h b/firmware/target/arm/s3c2440/gigabeat-fx/timer-target.h
index ac195bf9a5..b5652a3365 100644
--- a/firmware/target/arm/s3c2440/gigabeat-fx/timer-target.h
+++ b/firmware/target/arm/s3c2440/gigabeat-fx/timer-target.h
@@ -23,6 +23,7 @@
 
 /* timer is based on PCLK and minimum division is 2 */
 #define TIMER_FREQ (49156800/2)
+#define TIMER234_PRESCALE 21
 
 bool __timer_set(long cycles, bool set);
 bool __timer_register(void);
diff --git a/firmware/target/arm/s3c2440/gigabeat-fx/wmcodec-meg-fx.c b/firmware/target/arm/s3c2440/gigabeat-fx/wmcodec-meg-fx.c
index 957d58b344..de965f0750 100644
--- a/firmware/target/arm/s3c2440/gigabeat-fx/wmcodec-meg-fx.c
+++ b/firmware/target/arm/s3c2440/gigabeat-fx/wmcodec-meg-fx.c
@@ -29,8 +29,14 @@
 #include "kernel.h"
 #include "sound.h"
 #include "i2c-meg-fx.h"
+#include "system-target.h"
+#include "timer-target.h"
 #include "wmcodec.h"
 
+#ifdef HAVE_HARDWARE_BEEP
+static void beep_stop(void);
+#endif
+
 void audiohw_init(void)
 {
     /* GPC5 controls headphone output */
@@ -39,6 +45,14 @@ void audiohw_init(void)
     GPCDAT |= (1 << 5);
 
     audiohw_preinit();
+
+#ifdef HAVE_HARDWARE_BEEP
+    /* pin pullup ON */
+    GPBUP &= ~(1 << 3);
+    beep_stop();
+    /* set pin to TIMER3 output (functional TOUT3) */
+    GPBCON = (GPBCON & ~(0x3 << 6)) | (2 << 6);
+#endif
 }
 
 void wmcodec_write(int reg, int data)
@@ -48,3 +62,92 @@ void wmcodec_write(int reg, int data)
     d[1] = data;
     i2c_write(0x34, d, 2);
 }
+
+#ifdef HAVE_HARDWARE_BEEP
+/** Beeping via TIMER3 output to codec MONO input **/
+static int beep_cycles = 0;
+static int beep_cycle_count = 0;
+
+static void beep_stop(void)
+{
+    int oldstatus = disable_interrupt_save(IRQ_FIQ_STATUS);
+
+    /* stop interrupt */
+    INTMSK |= TIMER3_MASK;
+    /* stop timer */
+    TCON &= ~(1 << 16);
+    /* be sure timer PWM pin is LOW to avoid noise */
+    TCON ^= (GPBDAT & (1 << 3)) << 15;
+    /* clear pending */
+    SRCPND = TIMER3_MASK;
+    INTPND = TIMER3_MASK;
+
+    restore_interrupt(oldstatus);
+}
+
+/* Timer interrupt called on every cycle */
+void TIMER3(void)
+{
+    if (++beep_cycles >= beep_cycle_count)
+    {
+        /* beep is complete */
+        beep_stop();
+    }
+
+    /* clear pending */
+    SRCPND = TIMER3_MASK;
+    INTPND = TIMER3_MASK;
+}
+
+void pcmbuf_beep(unsigned int frequency, size_t duration, int amplitude)
+{
+    #define TIMER3_TICK_SEC (TIMER_FREQ / TIMER234_PRESCALE)
+
+    unsigned long tcnt, tcmp;
+    int oldstatus;
+
+    if (amplitude <= 0)
+    {
+        beep_stop(); /* won't hear it anyway */
+        return;
+    }
+
+    /* pretend this is pcm */
+    if (amplitude > 32767)
+        amplitude = 32767;
+
+    /* limit frequency range to keep math in range */
+    if (frequency > 19506)
+        frequency = 19506;
+    else if (frequency < 18)
+        frequency = 18;
+
+    /* set timer */
+    tcnt = TIMER3_TICK_SEC / frequency;
+
+    oldstatus = disable_interrupt_save(IRQ_FIQ_STATUS);
+
+    beep_cycles = 0;
+    beep_cycle_count = TIMER3_TICK_SEC * duration / (tcnt*1000);
+
+    /* divider = 1/2 */
+    TCFG1 = (TCFG1 & ~(0xf << 12)) | (0 << 12);
+    /* stop TIMER3, inverter OFF */
+    TCON &= ~((1 << 18) | (1 << 16));
+    /* set countdown */
+    TCNTB3 = tcnt;
+    /* set PWM counter - control volume with duty cycle. */
+    tcmp = tcnt*amplitude / (65536*2 - 2*amplitude);
+    TCMPB3 = tcmp < 1 ? 1 : tcmp;
+    /* manual update: on (to reset count), interval mode (auto reload) */
+    TCON |= (1 << 19) | (1 << 17);
+    /* clear manual bit */
+    TCON &= ~(1 << 17);
+    /* start timer */
+    TCON |= (1 << 16);
+    /* enable timer interrupt */
+    INTMSK &= ~TIMER3_MASK;
+
+    restore_interrupt(oldstatus);
+}
+#endif /* HAVE_HARDWARE_BEEP */